One Electron specializes in audio circuit design, with
an emphasis on vacuum tube designs. Most designs have been targeted
to the "high-end" consumer audio market, but One Electron
has design capabilities in other areas, such as lower-cost consumer
products and pro-audio. Some recent designs include:
- Sans Pareil output-transformerless (OTL) amplifier
(Fourier Components, St. Peters, MO) - substantial redesign of driver
and bias circuits, based on original Futterman design.
- Triomphe stereo output-transformerless (OTL) amplifier
(Fourier Components, St. Peters, MO) - circuit design.
- CDV-1 CD player (Dynaco, a division of Panor Corp.,
Hauppauge, NY) - upgraded original tube line stage and power supply.
- PAS-5 remote-control preamplifier (Dynaco, a division of
Panor Corp., Hauppauge, NY) - design of tube tone control and line
- CDV-Pro CD player (Dynaco, a division of Panor Corp.,
Hauppauge, NY) - complete design of digital filtering, D/A converter,
I/V stage, line amp, and power supply.
- The Randall Amplifier - a high-quality
all-tube single-ended stereo power amplifier for a construction class.
- TMX-420 Four-channel Mixer (Summit Audio Inc., Soquel, CA)
- complete design of 4-channel-in, 2-channel-out rack-mount
high-quality mixer for Pro-audio applications.
- Consulted on the design of various tube-based preamps and power
amps for Canary Audio.
- LA-1 Line Amplifier, the PH-1 and PL-1
Phono Preamps, SP-1 Power Amp,
and SA-1 Motor Controller for (Artemis
Labs, Simi Valley, CA) - complete design of high-end audio products.
- Designed various custom tube-based preamps and power amps for
- Designed and built preamps and power amps for John Atwood's
A key part of One Electron's stable of test equipment is a
fully loaded Audio Precision
System Two (Dual Domain Cascade). This instrument permits exceptional
tests and measurements to be done in the audio band, and can test
and evaluate digital audio interfaces. Testing using the System
Two is available on a consulting basis.
One Electron has good background in general analog circuit
design and microcontroller-based digital design.
Some recent designs include
- Front-end analog circuit for new UV laser Dosemeter for OAI
(Optical Associates, Inc.)
- Custom sweep tube tester for Antique Electronics Supply, Inc.
- Transmitting tube tester for Artemis Labs.
- Custom computer-controlled tube testing and matching system for
Antique Electronics Supply, Inc.
- Custom vacuum-tube burn-in fixture for Antique Electronics
- Design and construction of five Apex Tube Matching systems for CE Distribution.
One Electron has printed circuit board (PCB) design
experience, and uses the latest releases of Altium's design software.
In addition to One Electron's own PCB
designs, One Electron has done PC layout on a consulting basis
- Sequoia Circuits: 256Kbyte and 1 Mbyte PowerPC cache cards (4 and
- Pacific Microsonics, Inc.:
HDCD Evaluation boards (2 and 4 layers), customer CD player board,
design and layout of a Rhode & Schwartz tester interface.
- Canary Audio: Layout of CA-703 stereo SE amplifier board.
- Summit Audio, Inc.: All
boards in the TMX-420 Mixer (2 layers), re-layout of DCL-200
- Artemis Labs: All PC
board designs (2-layer analog).
Audio Design: 2- and 4-layer surface mount analog and digital
- Three different boards for the Apex Tube Matching system.
One Electron has basic chassis and panel mechanical design
experience. Mechanical designs include:
- Chassis design for Berkeley Audio Design Alpha DAC.
- All mechanical design for Artemis Labs Products (except
turntables and tone arm).
- Mechanical design for tube testing and burn-in units for Antique
Electronics Supply, Inc.
- Mechanical design and construction of Apex Tube Matching system.
Not exactly design services, but still a service is teaching.
John Atwood has taught both the construction classes at the Randall
Museum (see the Randall Amp write-up)
and several classes at Cogswell
College in Sunnyvale, California. Classes taught at Cogswell
include: Senior Project, Audio with Tubes, and Digital Audio.